Encrypting RSS with Bloglines, Blowfish and Greasemonkey

Applied Cryptography: Protocols, Algorithms, and Source Code in C, Second EditionBruce Schneier, author of the Blowfish encryption algorithm and Applied Cryptography, turned me on to this article on encrypting RSS using Bloglines, Greasemonkey and Blowfish. Unlike other proposals for serving encrypted syndicated content, this actually works today.

The method allows you to freely intermix encrypted and non-encrypted content within the same feed, and even within the same item within the feed. The content is decrypted using a Greasemonkey script when viewed in Bloglines.